### Full text

on PERSPECTIVE.
the Appearance of the Line A E, is a Part of
the Line E D. Now, ſince the Point A is in

the two Lines A B, A E; the Appearance of

the ſaid Point will likewiſe be in the Appear-

ances of the aforeſaid two Lines, and conſequent-

ly is in the Point a, the common Section of B V

and E D.

### 29.1.

page 16.

Fig. 5.

## 30. Remarks .

24. If the Diſtance of the Eye be ſo great, that

one of the Points of Diſtance cannot be deno-

ted upon the horizontal Line; another Point, F,

muſt be uſed, diſtant from the Point of Sight

by about one third, or fourth Part of the Di-

ſtance of the Eye. But then, a correſpondent

Part of the Perpendicular A B muſt be likewiſe

taken, and laid off from B to G, in the Baſe

Line.

25. And in this manner may the Repreſentation

of a very diſtant Point be found, if its Diſtance

from the Perſpective Plane be known, together

with the Place wherein a Perpendicular drawn

from that Point cuts the Baſe Line. For, having

firſt drawn a Line, as B V, from the ſaid Point

of Concurrence to the Point of Sight, then B E

muſt be aſſum’d in the Baſe Line; for Example,

equal to the tenth Part of the Diſtance of the

Point whoſe Repreſentation is ſought; and V H

in the Horizontal Line, likewiſe equal to the

tenth Part of the Eye’s Diſtance. Then C, the

Interſection of B V and E H, will be the Appear-

ance ſought.

Note, By this Method may be found the Deep-

nings in Pictures.

The Appearance of the Point A may yet be

otherwiſe found, without drawing the Line B V

from the Point A, in taking B I equal to B A,